Flooring panel or wall panel and use thereof

ABSTRACT

A building panel, such as a flooring panel or wall panel and a method of assembling the same into a floor, wall cladding, etc. The panel is provided with a locking means in the form of groove ( 6 ) and tongue ( 7 ) forming a tongue/groove joint for assembling of the panels. In a preferred embodiment, the groove ( 6 ) and the tongue ( 7 ) are made of water resistant material and formed with a snap-together joint.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 09/705,916,filed Nov. 6, 2000, now U.S. Pat. No. 6,421,970, which, in turn, is acontinuation-in-part of U.S. Ser. No. 09/637,114, filed Aug. 11, 2000,now U.S. Pat. No. 6,418,683, which, in turn, is a continuation-in-partof U.S. Ser. No. 08/894,966, filed Sep. 28, 1997, now U.S. Pat. No.6,101,778, which is a 371 of PCT/SE96/00256, filed Feb. 29, 1996, theentire disclosures of which are herein incorporated by reference

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a building panel, such as a flooringpanel or wall panel and the use thereof to form floors, walls, cladding,etc., by assembling a plurality of the panels. In one embodiment, thepanels have particular utility for flooring or cladding a wet room.

2. Description of the Related Art

During the last few years laminated floors have achieved and increasedin popularity and on many markets they are beginning to replace parquetfloors and wall-to-wall carpets. In the production of laminated floors adecorative thermosetting laminate is first produced. This laminateusually consists of a base layer of paper sheets impregnated withphenol-formaldehyde resin and a decorative surface layer comprising adecor paper sheet impregnated with melamine-formaldehyde resin. Thelaminate is produced by pressing the different layers at a high pressureand at an increased temperature.

The laminate thus obtained is then glued to a carrier of particle board,for instance, or used as such without any carrier and it is then calledcompact laminate. The laminated panel thus produced is then sawn up to anumber of floor boards which are provided with groove and tongue at thelong sides and the short sides thereof. Often the floor boards producedhave a thickness of about 7 mm, a length of 120 cm and a width of about20 cm. Thereby they can usually be put on top of an existing flooringmaterial at a renovation. According to another alternative, instead oneor more of the above decorative sheets can be laminated directly towardsa base sheet of particle board for instance.

At the assemblage of such a flooring, glue is normally applied in thegroove when the floor boards are assembled. Therefore, it will bedifficult to change a damaged board or to remove a whole flooring and,for instance, install it in another room.

To avoid the above problem efforts have been made to achieve floorboards which can be assembled without glue. One such construction isdisclosed in the U.S. Pat. No. 5,295,341. There the boards are providedwith groove and tongue in the usual way, but here a snap-together systemis included in the groove-tongue joint.

These floorboards can be assembled without glue. However, they have thedisadvantage that the joints between the boards will be flexible and notrigid. Moreover, the joint between adjacent boards is not tight. Thismeans that if the surface below the floor boards is not completely even,which is usually the case, a gap will be formed between the boards. Intothese gaps dirt and water can penetrate.

SUMMARY OF THE INVENTION

According to the present invention, the last mentioned problem has beensolved and a building panel, such as a flooring panel or wall panel,preferably of thermosetting laminate having two pairs of parallel sideedges has been brought about. Two of these side edges are provided witha locking means in the form of a groove and the other two are providedwith a tongue fitting in the groove whereby a tongue/groove joint forassembling of the panels is formed. The groove and the tongue are madeof a water resistant or water tight material and formed with asnap-together joint including one or more snapping webs or the like withcorresponding cooperating snapping grooves. In one embodiment, thegroove in front of the snap-together joint has an entrance opening andcontinues inside the snap-together joint into a stabilizing groove. Thetongue is formed with a rear neck intended to fit in the entranceopening and a forwardly protruding stabilizing part situated in front ofthe snap-together joint and intended for a tight fit in the stabilizinggroove, whereby connecting panels when assembled by the snap-togetherjoints and the stabilizing parts in the stabilizing grooves are fixed toeach other and prevented from unintentional separation while at the sametime a rigid floor covering or wall covering respectively with watertight joints and without unintentional gaps between the panels isobtained. In other embodiments, where the effect provided by thestabilizing groove and stabilizing part is not desired, thesestabilizing parts can be omitted.

According to one preferred embodiment two adjacent side edges of thepanel are provided with a groove and the other two side edges with atongue. In this embodiment, the panel is usually quadrilateral, such asrectangular, but it can also be square.

In square panels it is also possible to provide a pair of parallel sideswith a groove and the other pair with a tongue. However, the choice ofpattern on the surface layer of the panel is limited with this shape. Inother embodiments, the perimeter of the panel comprises three or five,or more, such as six or eight, side edges and the arrangement of thegrooves and tongues can be varied. The series of panels which areconnected to form a floor, wall, or other system need not all be of thesame shape.

It is preferred that the groove and the tongue are made of a water proofor water resistant material, such as a thermoplastic, a thermosettinglaminate, aluminum or a cellulosic product such as a wood fiber board,chipboard or particle board or a veneer impregnated or coated with awaterproofing material, such as oil, wax or a thermoplastic orthermosetting substance including, but not limited to, polymeric resins.It has been found that treating the panel with a liquid plasticsubstance such as a polyurethane gives excellent results. Of course,also other waterproof, water tight or water resistant materials can beused.

In another embodiment, the groove, as well as the tongue, are formed asa ledge fixed to the side edges of the panel. Suitably the ledge-formedgroove and tongue respectively are then fixed in a recess along the sideedges with glue, for instance. Alternatively, the integral tongue andgroove portions of the panels can be formed in either the base material,the laminate material and/or both.

Protrusions which form the snapping webs can be formed on the upperand/or lower side of the tongue while cooperating depressions which formthe snapping grooves are formed in the groove.

In one preferred embodiment one snapping web is formed on the upper sideof the tongue and one on the lower side thereof while the groove has twofitting snapping grooves one at the top and one at the bottom of thegroove. These snapping webs may be diametrically opposite one another oroffset from one another. The corresponding snapping grooves will bepositioned according to the position of the snapping webs so as tocooperate therewith. In an alternative, but equally preferredembodiment, the tongue may be provided with an uneven number of snappingwebs on the upper and lower side of the tongues, e.g., none above andone below, one above and two below, etc.

If necessary one pair of snapping webs can be formed on the upper sideof the tongue and one pair on the lower side thereof. Of course, youthen need two snapping grooves at the top and two snapping grooves atthe bottom of the groove to fit with the snapping webs. Thisconstruction will give an extremely strong joint.

Of course, in all these embodiments, the snapping webs can be arrangedin the groove and the snapping grooves on the tongue. A greater numberof snapping webs may also be positioned above the tongue than below thetongue without departing from the invention.

In the preferred embodiment using the stabilizing parts, the width ofthe stabilizing part is 1-10 mm, preferably 2-10 mm, most preferably4-10 mm. Generally, a wider stabilizing part with fitting stabilizinggroove gives a better rigidity of the assembled panels.

The stabilizing part will also assist in a correct assemblage of thepanels. Thus, when the stabilizing part moves into the stabilizinggroove you get a correct level of the panels and the panels can easilybe pushed into the correct position where you do not have any gapbetween the panels. Of course, without any substantial gap between thepanels, water and dirt are prevented from entering the assembled panels,flooring or wall covering.

As a safeguard against water penetration a seal might be arranged in theinner part of the stabilizing groove for instance. Alternatively, byselectively engineering the materials used in the tongue and/or grooveportions of the panel of water resistant or water proof materials ofsuitable geometry and elastic modulus, the snapping action can befacilitated by permitting displacement or flexing of the elementsdefining the tongue and/or groove while the resilience permits snappingof the locking feature to bring said panels into forming a tight jointsuch that the joint is said to be waterproof or water tight. A joint iswater tight when standing water will not penetrate the joint for severalhours.

Notwithstanding that the joint is tight to the point of being waterproofor water tight, the panels may be dismountable from each other aftersnapping the panels together.

Preferably the grooves and the tongues run the full length of the sideedges of the panels, although they may be intermittently interruptedalong the length of the panels.

The panels can be designed in such a manner that the underside of thegroove and/or the tongue are situated in the same level as the undersideof the panel.

The panels can be used for covering floors and walls in ordinary dryrooms. However, due to the tight joints and in other cases due to therigid and water tight joints, the panels can be used also for wet rooms.For such applications the whole panel is preferably made of plastic orthermosetting laminate of so-called compact laminate type. Such alaminate does not absorb water.

Another alternative is a water resistant and/or non water-absorbing basewith a water tight surface. The surface may, for instance, consist of apaint, a thermoplastic foil such as polyethylene, polypropylene orpolyvinyl chloride, a paper sheet impregnated with a resin, such as athermosetting or UV-curing resin such as one comprising acrylate and amaleimide, or of a thermosetting laminate.

One suitable non water-absorbing base is a board produced by pressingand consolidating wood particles or wood chips impregnated with athermoplastic.

The invention will be further explained in connection with the enclosedfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a panel 1 according to the invention seenfrom above. The panel is drawn as a rectangular shape but it can just aswell be square or other quadrilateral.

FIGS. 2 and 3 show a cross section through two adjacent edges of twoembodiments of a panel where two such panels are to be assembled.

FIG. 4 is a schematic representation of a joint between two panelscontaining offset snapping webs on the tongue.

FIGS. 5-7 are schematic representations of three other embodimentsshowing different placements, number and arrangements of snapping websand snapping grooves on panels.

FIG. 8 is a schematic representation of a joint between two assembledpanels in another embodiment of the invention.

FIGS. 9-12 are schematic representations of four other alternativeembodiments showing different placements, number and arrangements ofsnapping webs and snapping grooves on panels.

FIGS. 13-16 disclose various methods of assembling the panels into afinished structure, such as a floor.

FIGS. 17-19 are partially sectional views through the groove side of thepanels of the invention which show the various positions of a snappinggroove in relation to an upper edge of the panel and a plane P passingvertically downward from said upper edge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The panel 1 consists of a base of cellulosic materials, such as woodparticles impregnated with a resin, such as a thermoplastic material,with a decorative thermosetting laminate as a surface layer 17 glued ontop.

The panel 1 has two pairs of parallel side edges 2, 3 and 4, 5respectively (FIG. 1). Two of these side edges are provided with lockingmeans in the form of a groove 6 and the other two with a tongue 7fitting in the groove 6, whereby a tongue/groove joint for assembling ofthe panels is formed.

The groove 6 and the tongue 7 are made of a water tight material andformed with a snap-together joint. In the embodiment shown in FIG. 2,the snap-together joint consists of two snapping webs 9, one on theupper side of the tongue 7 and one on the lower side of tongue, thesewebs 9 cooperating with two fitting snapping grooves 10.

In front of the snap-together joint, which means the snapping webs 9 andthe snapping groove 10, the groove 6 has an entrance opening 8. Insidethe snap-together joint the groove 6 continues in a stabilizing groove13.

The tongue 7 is formed with a rear neck 11 intended to fit in theentrance opening 8 of the groove 6. In front of the snap-together jointthe tongue 7 has a forwardly protruding stabilizing part 12 intended fora tight fit in the stabilizing groove 13.

The parts 9 and 10 included in the snap-together joint are also adaptedto each other to give a tight fit and strong joint. To increase thiseffect further the snapping grooves 10 are provided with undercut edges18 which cooperate with the backside of the snapping webs 9 with thesame undercut. As can be seen in various of the drawing figures of thepanels, the undercut edges 18 slope downwardly from a distal edge of thepanel towards the panel. The angle of slope is not critical. Although,in some embodiments, the angle represents a vertical drop, in manyembodiments the slope is not vertical.

In the embodiment of FIGS. 2 and 3, the groove 6 and the tongue 7 aremade of thermosetting laminate and formed as a ledge fixed by glue in arecess along the side edges of the panel. The under side 14 of thegroove 6 is situated in the same level as the under side 15 of the paneland the under side 16 of the tongue 7 is situated in the same level asthe under side 15 of the panel 1. In the embodiments of FIGS. 4-12, thetongue and groove are formed of the same material as the body of thepanel. Thus, when the body of the panel comprises a carrier of a resinimpregnated cellulosic material, such as fiber board, the tongue andgroove are formed of the same material as the carrier of the panel. Inother embodiments, the base or carrier itself can be formed of a waterrepellent material, such as plastic. When pushed together, the panelsmake a distinctive sound, which we have nicknamed the “click” system.

When connecting panels have been assembled by the snap-together jointsand the stabilizing parts 12 inserted in the stabilizing grooves 13, thepanels are fixed to each other and prevented from unintentionalseparation. A rigid floor covering or wall covering with water tightjoints and without unintentional gaps between the panels is obtained.The usual rotation of the snapping webs 9 in the snapping grooves 10 isprevented by the stabilizing parts 12 in the stabilizing grooves 13.Accordingly these parts are essential for the possibility to get a rigidjoint between the panels.

The embodiment shown in FIG. 3 is very similar to that according to FIG.2. The difference is that only the under side of the tongue 7 isprovided with a snapping web 9. The upper side is lacking a snappingweb. Accordingly there is only one snapping groove 10 at the bottom ofthe groove 6.

The embodiment of FIG. 4, though similar to FIG. 2 in having the upperand lower sides of tongue 7 provided with snapping webs 9, such snappingwebs are longitudinal displaced along tongue 7.

The embodiment of FIG. 5 shows the provision of an uneven number ofsnapping webs 9 on tongue 7 where an upper and lower snapping web arevertically aligned but a third snapping web, positioned on the undersideof the tongue 7 is longitudinally displaced at a distance towards themain body of the carrier.

In FIG. 6 is illustrative of a further embodiment, similar to that ofFIG. 4 in having longitudinally displaced upper and lower snapping webs9. However, in FIG. 6 is provided a nose 19 on the upper edge of panel1, proximate the tongue side of the panel. Such nose 19 assists inproviding a tight joint when similar panels are assembled together. Thenose may alternatively be provided on the groove side of the panel orfurther on both the tongue and groove sides of the panel.

FIG. 7 illustrates the same type of nose 19 as in FIG. 6, however, inthis embodiment, the lower snapping webs 9 are both longitudinallydisplaced towards the main body of panel 1 such that the most distalsnapping web 9 lies vertically beneath nose 19 and the other snappingweb 9 is inwardly positioned.

The embodiment of FIG. 8 illustrates a unique design for both tongue 7and snapping webs 9 and snapping grooves 10. In this embodiment, tongue7 is undercut so as to provide a sloping surface 20. Moreover, the wallsof the backsides of snapping webs 9 and the corresponding walls ofsnapping grooves 10 are vertical, or nearly so. This configurationpermits at least one of the panels to be tilted relative to the otherpanel to provide for disassembly of the floor panels. The sloped surface20 accommodates such tilting and thus, the disassembly of the panels.Moreover, the radius covers 21, 22 of the panels edges facilitate the“turning” of the assembled panels away from each other.

As in the embodiments of FIGS. 2 and 3, each of the embodiments of FIGS.4-8 may comprise an upper surface of a thermosetting laminate, a plasticfoil such as an olefin plastic, paper sheets impregnated with athermosetting or UV-curing resin comprising acrylate and a maleimide orsimilar materials.

In FIGS. 9-12, a panel 1 comprises a base of cellulosic material 11 witha decorative surface 17. The decorative surface 17 can be athermosetting laminate, a plastic foil, such as an olefin plastic, papersheets impregnated with a thermosetting or UV-curing resin comprisingacrylate and a maleimide or similar materials. The cellulosic material11 is the same as or similar to that used in the embodiments of FIGS.1-8. However, as shown in FIG. 9, groove 16 contains an upper snappinggroove 99 and a lower snapping groove 23. While each of groove 99 and 23are vertically overlapping with each other, they are not coextensive.Snapping groove 99 is positioned proximate the groove edge 31 andsnapping groove 23 extends further distal to groove edge 31, though bothgroove 99 and groove 23 are located with an imaginary vertical plane Pextending through the top of panel edge 40. In each of the variousembodiments illustrating vertical plane P, the upper edge is located asshown by 40 in FIG. 9. On the tongue side of panel 1 of FIG. 9 are twosnapping webs 34, 35, configured and located so as to snap intocooperating grooves 99 and 23 on an identical panel (not shown).

In FIG. 10, is a panel constructed similarly to that of FIG. 9, with themodification that two upper snapping grooves 97, 98 and one lowersnapping groove 101 are provided. As can be seen in FIG. 10, the upperand lower snapping grooves engage with corresponding upper snapping webs103, 104 and lower snapping web 105 when a similar panel 1 is located soas to check or snap into place.

FIG. 11 is similar to FIG. 9 except that the position of upper and lowersnapping grooves 199, 123, respectively, are offset as shown.Additionally, lower web 106 of groove edge 31 extends distally beyondplane P which is an imaginary vertical plane extending through the topweb 116 of groove 31.

Snapping webs 203, 205 are configured so as to be received withcorresponding snapping grooves 199, 123, respectively, when an identicalpanel is horizontally pushed into place.

FIG. 12 is similar to FIG. 10 except insofar as the lower web 206extends distally beyond imaginary plane P extending vertically from thetop edge 216 of groove 31. As in the previous figures, upper and lowersnapping webs 303, 304, 305 are configured so as to be matingly receivedin snapping grooves 297, 298 and 301 of an identical panel.

FIGS. 13-15 are illustrative of various ways to assemble the panelsaccording to the invention. In each of these Figs. A and B represent twopanels assembled in a first row, C represents a first panel assembled ina second row and D represents a new panel to be assembled so as toadjoin said first and second rows. All of such new panels D areassembled by horizontally pushing the new panel D in one of thefollowing steps.

In FIG. 13, new panel D is engaged at its “short side” 401 with a shortside 402 of panel C and is horizontally pushed in the direction of arrow501 so as to slide along the short side 402 of panel C with panel D'srespective upper and lower snapping webs are received in the respectiveupper and lower snapping grooves of panel C and until the “long sides”403 of panel D engages with the edges 404, 405 of panels A and B.

In the alternative installation method of FIG. 14, new panel D isengaged at its long side 403 with the long side 405 of panel B andhorizontally moved along arrow 602 until panel D's short side 401engages with short side 402 of panel C. The horizontal motion does notrequire that any of the panels be “tilted” or “angled” out of the planeof the paper in order to joint the new panel D with any of thepreviously laid panels A-C.

Still further, new panel D may be simultaneously assembled with shortside 402 of panel C and the long sides 404 and 405 of panels A and B byexerting a force in the direction of arrow 202 as shown in FIG. 15. Aspecial tapping block (not shown) configured to engage with the tongueand groove segments of new panel D can be used to horizontal urge panelD into simultaneous engagement with each of panels A, B, and C.

FIG. 16 shows a “double” horizontal push method of assembling a newpanel into engagement with previously laid panels. In this embodiment,new panel D is placed with its long side 403 at a distance (forinstance, 2 cm) from the long sides 404 and 405 of panels A and B,respectively. Then the new panel D is pushed horizontally in thedirection of arrow “a” until the short side of 401 of panel D snapstogether with the short side 402 of panel C. Then, panel D is pushedhorizontally in the direction of arrow “b” (while still engaged withpanel C along the joint formed by short side 402 of panel C and shortside 401 of panel D) until the side 403 of panel D snaps together withthe long sides 404 and 405 of panels A and B, respectively.

FIGS. 17-18 illustrate various locations for the placement of theimaginary plane P with regard to the distal corner of the rear wall ofthe lower snapping groove. Thus, in FIG. 17 (which is similar to FIG.11), the plane P may intersect the upper corner 249 of the rear wall 250of the lower snapping groove 123.

FIG. 18 shows that the corner 249′ is placed slightly inwardly of planeP at a distance X which can be as little as 0.04 to 0.10 mm inside(towards the panel) of plane P. Of course, other embodiments, such asFIGS. 9-12, show the plane P passing quite outside the snapping groove.

FIG. 19 is a further embodiment illustrating the passage of plane Pthrough the snapping groove 123 with the corner 249″ well distal ofplane P.

Of course, FIG. 6 shows snapping groove 23 well distal of plane P.

It will be understood by those skilled in the art that the tongue sideof panel 1 in each of FIGS. 17-19 has a configuration to mate with thesnapping grooves 123 of FIGS. 17-19.

Thus, we have disclosed not only a configuration of making panels havingunique tongue and groove configurations which permit “glueless” assemblyof the panels by a click system, but also a method of assembling suchpanels into a finished structure, such as a floor.

The body of the panels in the embodiments are intended to be assembledwithout glue, but certainly glue or other sealing substance could beapplied to the vicinity of the joint. Especially in the embodimentswhere the panels are intended to be installed in or proximate wet rooms,but also in ordinary rooms, the panels, especially the tongue and grooveportions, can be coated or impregnated with a waterproofing material,such as an oil, wax, paint or other waterproofing material such as aliquid plastic coating, like polyurethane.

Alternatively, instead of a waterproof or water resistant layer on acarrier, the entire panel body can be made of a waterproof material,such as plastic, in which case the tongue and groove portions may bemade of the same material as, and a unitary part of, the panel.

In still another embodiment of the invention, the joints can be“pre-glued,” i.e., have a glue system applied at the factory which gluesystem can be activated upon assembly of the panels 1 into a finishedstructure, such as a floor. For example, the friction applied byassembling the panels as in FIGS. 13-16 can be used to rupturemicroballoons containing a catalyst or other component of an adhesivesystem to cause the assembled panels to be adhesively connected at thejoint upon assembly.

Alternatively, the tongue portion of the panels can be pre-coated withone component of a two component adhesive system and the groove portioncan be pre-coated with another component of the two component system,such that upon assembly of the tongue and groove portions of twoadjacent panels, the adhesive system is activated to cause the panels tobe adhesively connected at their joint.

It is within the scope of this adhesive system to include a blowingagent so as to form a foam filled adhesive. Alternatively, the adhesivemay act more as a sealant, sealing the joint against ingress of water orother liquids when the panels are assembled into a structure, such as afloor.

Other adhesive systems, such as the use of initiators, inclusion ofblowing or gas generating agents, multipart systems, such as a two resinsystem comprising parts one and two, wherein the catalyst or curingagent for part one is included with the part two resin and the catalystor curing agent for part two is included with the part one resin may beapplied at the factory, and initiated when the panels are installed.

Initiation may also occur when a protective strip is removed from thepanel edges just prior to assembly of the panel, the removal of theprotective strip exposing reactive components of the adhesive system.

Such modifications of the above pre-glued system will be apparent tothose skilled in the art upon reading this disclosure.

It should be appreciated that we have provided a building panel andmethod of assembling the same which will result in tight joints betweenpanels such that the assembled panels, used as flooring or cladding,which will be water repellent, that is, impervious to water standing onthe surface of the joint, whether or not a pre-glued system is appliedto the panel.

The invention is not limited to the embodiments shown and describedsince these may be readily modified by those of ordinary skill in theart to which this invention pertains without departing from the scope ofthe appended claims.

We claim:
 1. A method of forming a joint between similar panels, saidmethod comprising: providing a series of panels, said panel defining aperimeter, said perimeter defining at least three sides of said panel,providing at least one tongue or groove shape along said sides, definingat least two protrusions on at least one of said tongue or groove to actas a snapping web and defining at least two depressions on at least oneof said tongue and groove, the at least two depressions being positionedso as to act as a snapping groove to receive said snapping web, andurging the panels together to form said joint wherein said snapping weband snapping groove urge the panels together to form said joint whereinat least one of said at least two protrusions are vertical offset fromat least one other of said at least two protrusions.
 2. The method ofclaim 1, wherein the panels are quadrilateral and two sides have tonguesand two sides have grooves and the panels are assembled by snapping thetongues into said grooves.
 3. The method of claim 1, wherein saidprotrusions are on said tongue and the panels are assembled by snappingsaid protrusions into depressions in said groove.
 4. The method of claim1, wherein said panels maybe disassembled by rotating at least one ofsaid panels about said joint to dismount said panels.
 5. The method ofclaim 3, wherein there is at least one additional protrusions on saidtongue.
 6. The method of claim 5, further comprising providing at leastone additional depression in said groove so as to cooperate with each ofsaid at least one additional protrusions.
 7. A system for forming awall, floor or cladding by assembling a plurality of panels into aninterlocked unit, said system comprising: a plurality of panels, each ofsaid panels defining a perimeter having at least three sides; each ofsaid sides being provided with at least one of a tongue or a groove,said panel comprising an upper surface formed of paint, a thermoplasticfoil, a paper impregnated with a thermosetting or UV-curing resin, or athermosetting laminate; at least one of the tongue and groove beingprovided with at least two protrusions and the other being provided withat least two depressions cooperating with said protrusions to form asnapping web and snapping groove, respectively; said snapping web andsnapping groove forcing adjacent panels towards the joint when saidpanels are snapped together, wherein at least one of said at least twoprotrusions are vertically offset from at least one other of said atleast two protrusions.
 8. The system of claim 7, wherein at least one ofthe panels comprises a nose extending outwardly along an upper surfaceof the perimeter.
 9. The system of claim 7, wherein the panels arequadrilateral.
 10. The system of claim 7, wherein the joints formed insaid interlocked unit are water resistant.
 11. The system of claim 7,wherein the panels are formed of an upper surface adhered to a baselayer and the base layer is treated so as to increase its waterresistance properties.
 12. The system of claim 7, wherein the base layeris formed of a compressed cellulosic impregnated or coated with a wax,an oil, or a resin.
 13. A building panel, said panel having a perimeterdefining at least three sides, said sides being provided with at leastone of a tongue or a groove, said panel comprising an upper surfaceformed of a paint, a thermoplastic foil, a paper impregnated with athermosetting or UV-curing resin or a thermosetting laminate; at leastone of said tongue and groove being provided with at least twoprotrusions and the other being provided with at least two depressionscooperating with said protrusions to form a snapping web and snappinggroove, respectively; said snapping web and snapping groove forcingadjacent panels towards the joint where said panels are snappedtogether, wherein at least one of said at least two protrusions arevertically offset from at least one other of said at least twoprotrusions.
 14. The building panel of claim 13, wherein said panel is aquadrilateral.
 15. The building panel of claim 14, wherein there is atleast one additional protrusion in addition to said at least twoprotrusions.
 16. The building panel of claim 14, wherein saidprotrusions are even in number and are vertically offset.
 17. Thebuilding panel of claim 15, wherein none of said protrusions arediametrically opposed.
 18. The building panel of claim 15, wherein thereare at least three protrusions, two of which are diametrically opposed.19. The building panel of claim 14, wherein there are an even number ofprotrusions, but they are longitudinally displaced from each other. 20.The building panel of claim 19, wherein the tongue on which theprotrusions are located has a truncated lower surface.
 21. The method ofclaim 1, further comprising placing a sealant within said joint.
 22. Themethod of claim 21, wherein said sealant is a preglue, wherein saidpreglue is applied at a factory and activated upon assembly of thepanels.
 23. The method of claim 21, further comprising applying apreglue to at least one of the tongue and groove shapes at a factory.24. The method of claim 23, wherein the preglue is applied to both thetongue and groove shapes at a factory.
 25. The method of claim 23,further comprising activating the preglue upon assembly of the panels.26. The system according to claim 7, further comprising a sealantbetween said tongue and groove portions.
 27. The system according toclaim 26, wherein said sealant is a preglue, wherein said preglue isapplied at a factory and activated upon assembly of the panels.
 28. Thesystem according to claim 26, further comprising a preglue on at leastone of the tongue and groove shapes.
 29. The system according to claim27, wherein the preglue is on both the tongue and groove shapes.
 30. Thebuilding panel of claim 13, further comprising a sealant on at least oneof the tongue and groove.
 31. The building panel of claim 30, whereinsaid sealant is a preglue.
 32. The building panel of claim 30, wherein apreglue is on at least one of the tongue and groove.
 33. The buildingpanel of claim 32, wherein the preglue is on both the tongue and glue.